Conclusion

All candidates produce a very smooth bokeh and good to excellent center sharpness already at open aperture - nothing else was expected in this price range.

Both 0.95ers are purely designed for maximum bokeh and subject separation at low light.
Their border and edge performance is mediocre and even at f/8 they can not cope with the resolution of the 36 MP sensor. Also in the midframe area half way between center and edges they show some weaknesses.

The Noctilux produces significantly more purple fringing at open aperture and has a slightly stronger field curvature and vignetting than the HyperPrime CINE. Stopped down to F1.4 you can already see some edges from the aperture blades in the bokeh highlight circles of confusion while the HyperPrime CINE keeps them round also stopped down.

The HyperPrime CINE has a stronger distortion as the other candidates and the particular copy used in this test had an asymmetric sharpness gradient indicating a decentration.

The Leica Summilux had the strongest field curvature. You can see the impact when you compare the photo of the fisherman below with that from the Otus. The Summilux produces a nice background blur around the separated fisherman but at the borders the background gets sharp again. This kind of creative effect is not always in demand...The last weeks we could often read that people are unsatisfied with the border and edge performance of the Summilux on the A7/A7R and tried to explain it with edge smearing caused by the sensor. In fact, here it is no edge smearing. Instead it is the result of field curvature as demonstrated with the test charts and the edge focused crops.

The Zeiss FE 1.8/55 delivers an surprisingly good result already at open aperture accross the whole image frame and has only very little field curvature. The only disadvantage is the missing 2/3 aperture compared to the f/1.4 lenses. Already at f/2.0 the Zeiss FE 1.8/55 begins to produce moiré in the reproduction of the rastered print what can not be accused to the lens. It is an indication that already the resolution of the AA-filterless 36 MP sensor is reached here.

The Zeiss Otus outperforms all other lenses in a degree I have never seen before. Even at open aperture it already reaches a resolution that the other lenses can not deliver before stopped down to f/4.0. Field curvature is negligible and edge resolution almost reaches the sensors resolution already at open aperture. At f/2.8 resolution and contrast are on a level that practically can not be raised anymore when attached to a 36 MP sensor. It seems that this lens is already designed to challenge sensors with 100+ MP.

Summarized I would say that the Zeiss FE 1.8/55 delivers best value for its price. Sometimes you may miss the 2/3 additional aperture but it shows extremely good performance across the whole frame already at open aperture and makes additional points with its AF capability (but the others can be manually focused with better feedback). For me it is the "Otus light".

The 0.95ers are pure bokeh specialists, whereas the Summilux has a little wider range of applicability if you can live with some of it's drawbacks. It is extremely compact for its level of performance.

The Otus marks a new reference. It delivers incredible detail, contrast as well as smooth bokeh across the whole image frame. It is a lens without any optical compromises but you will think twice before putting it into you photo bag due to its weight and size.